Lubricant



Patented Sept. 2, 1941 PATENT OFFICE LUBRICANT John M. Musselman, South Euclid, Ohio, assignor to The Standard Oil Company, Cleveland, Ohio,

a corporation of Ohio No Drawing. Application July 7,

Serial No. 283,25

6 Claims.

Lubricating oil in high temperature usage such as in internal combustion engines is subjected to drastic conditions which break down the oil and very greatly limit the durability of an oil which under more ordinary conditions of usage would maintain satisfactory properties. Efforts at improvement by incorporation of certain nitrogen compounds have been made. I have however found that a combination of certain diaryl compounds with certain halogenated carboxylic acids, in suchlubricating oils shows remarkable durability over lubricants heretofore known. This is all the more surprising, in view of the fact that 'the action of such carboxylic acid per se with the oil is without useful efieet, while the effect of my new combination is out of all proportion to the sum of the constituents.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described, and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a. few of the various ways in which the principle of the invention may be employed.

The oil may be of such stock and lubricant viscosity as desired, and for instance conveniently a lubricating stock of Mid-Continent type with viscosity 40 to 200 sec. Saybolt Universal at 210 F. The compounds of the diaryl diamines, preferably diaryl ethylenediamines, may be prepared by heating together, (as over a steam bath), the diamine and a halo-carboxylic acid having at least six carbon atoms. Molar proportions of the diamine and of the acid are preferred, although no difiiculty results if one component be in excess, there being in such eventmerely a dilution from the maximum possible. The diaryl ethylenediamine may be for instance symmetrical diphenylethylenediamine, di-o-tolyl ethylenediamine, etc. The halogenated carboxylic acid of at least six carbon atoms may be for instance chlorostearic acid, chloronaphthenic acid, chloropalmitic acid, and the like. Generally, the chlor-compound is preferred. Illustrative are symmetrical dlphenylethylenediamine dichlorostearate, symmetrical diphenylethylenediamine chloronaphthenate, symmetrica diphenylethylenediamine dichloropmtate, 'di-otolyl ethylenediamine dichlorostearate, di-o-tolyl ethylenediamine dichloropalmitate, di-o-tolyl ethylenediamine chloronaphthenate, etc. Such compound is readily soluble in the oil, and may be incorporated therein in amounts of for instance 0.01 to per cent, but most generally an amount of 0.5 per cent is desirable. In internal combustion engine usage the body of the oil is well maintained, and such difliculties as sticking of piston rings etc. are particularly inhibited. I

10 As an example: A Mid-Continent S. A. E. 30

oil is compounded with 0.5 per cent of symmetrical diphenylethylenediamine chloronaphthe nate.

As another example: With a similar oil there is incorporated 0.5 per centof di-o-tolyl ethylenediamine dichlorostearate.

As another example: With a similar oil there is incorporated 0.5 per cent of di-o-tolyl ethylenediamine naphthenate.

As another example: With a similar oil there is incorporated 0.5 per cent of symmetrical diphenylethylenediamine dichlorostearate.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distictly claim as my invention: 30 l. A lubricating oil containing a small amount of a diaryl ethylenediamine compounds of a halogenated carboxylic acid having at least sixcarbon atoms.

2. A lubricating oil containing a small amount.

' JOHN M. MUSSEIMAN.

diphenylethylenediamine di- 

